• Journal of the Korean Institute of Gas
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• v.5 no.1
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• pp.52-59
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• 2001

Factors to cause accidents were investigated through a systematic analysis of leakage accidents in welded LP-gas cylinder between 199 and 1999. As a result It was showed that most of leakage accident occurred at the pin-hole due to the localized corrosion on welded zone in cylinder. Accordingly, in this paper, we suggested that the problems of heat treatment condition in two-piece welded cylinder and substitute proposal for preventing the tearing of T zone in three-piece welded cylinder. Furthermore, corrosion rate on the weldment and base metal of welded LP-gas cylinder was evaluated using the electrochemical tests in acid rain and $3.5\%NaCl$ solution, Also, the poor adhesion and defects of film which was produced by electrostatic powder spray painting, while the LP-gas cylinder was manufactured, were analyzed using SEM(Scanning Electron Microscopy). And we proposed a optimum coating thickness of the cylinder.

• Journal of the Korean Institute of Gas
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• v.16 no.1
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• pp.46-50
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• 2012

The performance of the Type3 hydrogen composite cylinder whose pressure is 70 MPa using hydrostatic cycling test equipment was evaluted in this study. It also includes the finite element method analysis on the performance of the cylinder when the pressure is applied. As a result, cylinder body parts of the Type3 hydrogen composite cylinder, which draws attention with its safe status and the lightness, was ruptured first and the same result has been found out through the finite element method. The dome knuckle and the cylinder body were proved as the weakest parts since the cylinder body parts was expanded under the pressure.

• Journal of the Korean Institute of Gas
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• v.26 no.1
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• pp.34-40
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• 2022

Gas cylinder cabinets have risks such as cylinder explosion and scattering of debris when a fire occurs. These risks are likely to cause gas spills and cause secondary damage. In order to reduce damage, it is very important to secure the fire resistance performance of the gas cylinder cabinet. In foreign countries, NFPA codes in the United States and EN-14470-2 in Europe stipulate fire resistance test standards for gas cylinder cabinets to protect internal cylinders for a certain period of time in a situation where gas cylinder cabinets are exposed to flames. However, in Korea, only internal pressure performance and airtight performance standards are specified, and the target is limited to piping, and research and regulations for the fire resistance performance of gas cylinder cabinets are insufficient compared to overseas. Therefore, in this study, finite element analysis was used to establish fire resistance standards for domestic gas cylinder cabinets. In the event of a fire, optimal conditions are derived in terms of structure and material.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.74-81
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• 2020

In general, when manufacturing a semiconductor, a number of hazardous and dangerous substances such as flammability, toxic, and corrosiveness are used. In particular, semiconductors are manufactured using specialty gas in processes such as CVD and etching. The specialty gas is filled in a container in the state of compressed or liquefied gas, and a gas cylinder cabinet is used as a facility for supplying this specialty gas to the semiconductor manufacturing process. When a accident occurs in the gas supply system, gas is released through a pressure release device installed in the gas cylinder to secure the safety of the supply system. In this case, the gas released inside the gas cabinet, there is a risk of leaking to the outside. After that, by analyzing the gas flow in the gas cabinet, it is intended to identify the risk associated with leak and to provide measures to prevent accidents.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.51-56
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• 2011

Mixed gas cylinder(80% Ar, 20% $O_2$) exploded three years ago. But the cause of cylinder rupture was not identified and the case was finished. This paper is the discussions on the cause of cylinder explosion with the investigation report by the police and the similar accident cases. The cause of explosion is the chemical reaction in the cylinder. This accident is similar with the explosion of pressurized oxygen cylinder.

• 연구논문집
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• s.23
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• pp.121-126
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• 1993

In general, natural gas engine converted from gasoline engine has disadvantage of power decrease. In order to increase power output in natural gas engine, the improvement of in-cylinder flow motion has been believed as the most effective method. In this study, the geometry of combustion chamber in 4 valve DOHC natural gas engine is modified, and in-cylinder flow patterns are analyized. Also engine performance is evaluated according to the modification of in-cylinder flow motion.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.1-6
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• 2012

This paper presents a stress safety of a composite pressure cylinder for a hydrogen gas vehicle. The composite pressure cylinder in which is composed of an aluminum liner and carbon fiber wound layers contains 104 liter hydrogen gas, and is compressed by a filling pressure of 70 MPa. The FEM computed results are analyzed based on the US DOT-CFFC basic requirement for a hydrogen gas cylinder and KS B ISO specification. The FEM results indicate that the stress, 255.2 MPa of an aluminum liner is sufficiently low compared with that of 272 MPa, which is 95% level of a yield stress for aluminum. Also, the composite layers in which are wound on the surface of an aluminum cylinder are safe because the stress ratios from 3.46 to 3.57 in hoop and helical directions are above 2.4 for a minimum safety level. The proposed composite pressure cylinder wound by carbon fibers is useful for 70 MPa hydrogen gas vehicles.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.36-40
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• 2015

To evaluate the safety of propane cylinder, the flame test was performed by the flame exposure scenario of propane cylinder. The cylinder which was exposed in a flame was rapidly occurred to increase the internal pressure by liquid expansion, if so it cause of physical explosion. Therefore, the cylinder which was applied with thermal pressure relief device sholud be not bursted and the propane should be discharged to outside safely. The flame average temperature that was around of cylinder is $600^{\circ}C$, and then it increased $700^{\circ}C$ by discharged propane. The result of flame test, the cylinder was deformed, but it was not bursted. The regulations of flame exposure test for propane cylinder were not restricted, this paper can be applied to restrict the flame test if the cylinder is possible to expose the flame. Also, the results is expected as reference for estimation of the pressure cylinder performance.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.98-103
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• 2015

Liquefied petroleum gas can be charged up to 85% of cylinder volume by enforcement regulations of safety control and business of liquefied petroleum gas act. The charged mass by enforcement regulations is considered by liquid expansion of internal liquefied petroleum gas at $65^{\circ}C$. But the temperature of liquid would not be suspended under $65^{\circ}C$ in a cylinder or portable vessel at certain situation. In the thermodynamics view point, the cylinder can be exposed to high pressure by liquid expansion. Consequently, it can be possible to potential risk such as physical explosion. Hence, this paper will offer a method of estimated internal pressure by liquid expansion at critical state in the closed system. Also, the structural factor which is given rise to volume increasement of cylinder is offered by experiment. This paper is expected as crucial reference for a cylinder design of liquefied petroleum gas.

• Journal of Mechanical Science and Technology
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• v.15 no.1
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• pp.108-116
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• 2001

The in-cylinder flow field of gasoline engine comprises unsteady compressible turbulent flows caused by the intake port, combustion chamber geometry. Thus, the quantitative analysis of the in-cylinder flow characteristics plays an important role in the improvement of engine performances and the reduction of exhaust emission. In order to obtain the quantitative analysis of the in-cylinder gas flows for a gasoline engine, the single-frame particle tracking velocimetry was developed, which is designed to measure 2-dimensional gas flow field. In this paper, influences of the swirl and tumble intensifying valves on the in-cylinder flow characteristics under the various intake flow conditions were investigated by using this PTV method. Based on the results of experiment, the generation process of swirl and tumble flow in a cylinder during intake stroke was clarified. Its effect on the tumble ratio at the end of compression stroke was also investigated.